The present invention relates to a mainspring mechanism and a device having such a mechanism, and more particularly, to the configuration of a driving mechanism which is suitable for use as an automatic opening and closing mechanism, or the like for a lid and a storage section.
In general, small mainspring mechanisms are used as driving sources for obtaining a driving force for various kinds of objects in various fields. Normally, a spiral mainspring is held inside a mainspring case called a barrel drum, and a rotating shaft connected to the inner end of the mainspring is rotatably supported in the center of the mainspring case. While only the rotating shaft is sometimes used as a unique driving-force output section in this case, for example, one of the rotating shaft and the mainspring case is sometimes used as an input shaft, and the other is used as an output shaft.
In the above-described mainspring mechanisms, since the driving force obtained after winding up the mainspring generally increases and decreases in accordance with the degree of winding of the mainspring, the driving speed varies depending on the degree of winding of the mainspring when a fixed driving load exists. Accordingly, as disclosed in Japanese Patent Publication No. 54-31146, a configuration (speed regulating mechanism) is adopted in which a braking plate rotatably held in a braking case filled with a fluid, such as liquid or powder, is connected to one end of a mainspring, and variations in the driving force of the mainspring are suppressed by the braking action of the braking plate, thereby reducing changes in driving force or driving speed.
However, while the above mainspring mechanism with the braking device has the configuration including the mainspring, the mainspring case, the braking plate, and the braking case, it must have a high sealing performance because it is necessary to fill the braking case for holding the braking plate with fluid or the like. Since it is also necessary to connect the braking plate and the mainspring, the configuration is usually quite complicated, the number of components is large, and it is difficult to reduce the production cost. Since the shape and structure are complicated, the mainspring case and the like are complicated, and it sometimes cannot be made of materials other than a plastic mold from a cost standpoint. This results in insufficient rigidity and insufficient durability of the mechanism in most cases. Furthermore, the overall mechanism is made thicker for similar reasons, and it is difficult to incorporate it in various devices.
Some of the conventional mainspring mechanisms having the braking device cannot perform efficient driving since the rotational load, such as frictional load, is increased due to size reduction and a simplified structure, and are difficult to be mounted in various devices since the configuration is special.
Furthermore, since the braking property is determined almost by the structure of the braking section, the material of fluid, and the like, the degree of flexibility in the structure of the braking section and in the selection of the material is low, and it is difficult to adjust the braking property of the assembled braking section.
Accordingly, the present invention aims to solve the above problems, and objects of the invention are to reduce the size and thickness of a mainspring mechanism having a braking device by adopting a configuration which can simplify the structure of the mainspring mechanism and which can reduce the number of components, to reduce the production cost of the mainspring mechanism, to provide a mainspring mechanism which can efficiently transmit the driving force and which can easily be mounted in various devices, and to provide a configuration in which the braking property of a braking section can easily be adjusted.
In order to achieve the above objects, a mainspring mechanism of the present invention includes a driving-force storing section having a mainspring to be wound up by a winding force so as to store a resilient force, a mainspring holding portion connected to the outer end of the mainspring so as to hold the mainspring therein, and a rotating member connected to the inner end of the mainspring and rotatably supported by the mainspring holding portion; an output device connected to the rotating member; and a braking section having a braking member connected to the rotating member so as to produce a braking force in response to the rotation of the braking member. According to this invention, since the rotating member is connected to the inner end of the mainspring, the diameter of the bearing portion of the winding stem supported by the mainspring holding portion is reduced, and the frictional load can be decreased. Furthermore, since the rotating member having the output device is placed on the inner side, the outer peripheral surface of the mainspring holding portion or the like can be easily attached to another member or the like. Since the rotating member is connected to the inner end of the mainspring, and also to the output device, the output device can be easily replaced and the shape and structure of the output device can be determined with more freedom by making the rotating member and the output device separate from each other. Therefore, it is possible to further reduce the size of the mainspring, and to reduce the production cost. The output device of the present invention may be formed of various structures, such as a gear, a gear train, a pulley, a chain, a belt, or a shaft.
Since the mainspring slowly stores and emits elastic energy because of the braking force produced by the braking section, the lifetime thereof is prolonged. The mainspring includes a constant torque spring and a coil spring which are used in such a manner as to receive and emit energy in response to changes in the winding state. The mainspring, the rotating member, and the mainspring holding portion may be connected by arbitrary device, such as press welding, hooking, or welding.
In the present invention, it is preferable that the driving-force storing section and the braking section be separate from each other. According to this invention, since the driving-force storing section and the braking section are separate, for example, in a case in which the driving-force storing section can independently operate, the braking section can be incorporated after the driving-force storing section is assembled, and the driving-force storing section can be removed from the production line before assembly of the braking component when a component, such as the mainspring, of the driving-force storing section is defective. For example, in a case in which the braking section can independently operate, since the driving-force storing section can be incorporated after the braking section is assembled, handling, management and the like of the components during assembly operation can be facilitated, for example, the braking section having the structure filled with a viscous fluid can be combined with another component after filling, or a plurality of braking sections having different braking forces can be prepared beforehand.
In the present invention, it is preferable that the braking section form a unit by itself. Herein, xe2x80x9cthe braking section forms a unit by itselfxe2x80x9d device that another component can be mounted into the braking section after the braking section has been completely assembled. According to this invention, since the braking section forms a unit by itself, it can be easily handled, and the assembly operation can be easily performed, for example, the braking section can be linked with the driving-force storing section in the final process of assembly. In particular, in a case in which the fluid is stored in the braking section, the braking section can be easily handled and managed with it being sealed. It is also possible to prepare a plurality of types of braking sections having different braking properties beforehand, and to selectively mount the braking sections in accordance with required properties of the product.
In the present invention, it is preferable that the rotating member and the braking member be separate from each other, and be linked with each other at least in the rotating direction. According to this invention, since the rotating member and the braking member are separate and are linked with each other in the rotating direction, it is possible to adopt an assembly procedure in which one of the driving-force storing section and the braking section is assembled first, and the other is then connected thereto. This can enhance assembly efficiency, for example, the components can be easily handled, and the assembly operation can be easily performed. While the rotating member and the braking member may be linked in the rotating direction by any structure engaged in the rotating direction, in particular, they are linked by, for example, an engaging structure between a groove crossing the center of rotation and a corresponding projection (for example, between a linear groove and a projection shaped like the tip of a flat-tip screwdriver) or an engaging structure between a polygonal recess and a polygonal projection (for example, a hexagon socket and a hexagon prism). The rotating member and the braking member may be press-fitted together. In this case, assembly efficiency is rather low, but both the members can be completely combined. Since the rotating member is rotatably supported in the mainspring holding portion, the structure for guiding the braking member is unnecessary.
In the present invention, it is preferable that the braking section has a cushioning mechanism for cushioning the rotational force transmitted from the driving-force storing section to the braking section. According to this invention, since the rotational force to be applied to the braking section can be cushioned by the cushioning mechanism, it is possible to prevent the braking section, the transmission mechanism, and the like from being broken when a great force is applied thereto. As the cushioning mechanism, a slip device, a clutch mechanism, or the like may be used.
In this case, it is preferable to place a slip device having a predetermined load resistance in the course of a rotation transmitting path from the rotating member to the braking member. In a case in which an excessive force is applied from the outside, or the braking force of the braking section increases due to a decrease in temperature, the slip device slips so as to suppress the transmission of rotation, and to reduce the load to be applied to the driving-force storing section and the braking section. Therefore, it is possible to prevent the mainspring mechanism from being damaged and broken. In this case, it is preferable that the braking member be in contact with a fluid and that the slip surface of the slip device be placed inside the fluid. In this case, since the slip surface of the slip device is placed inside the fluid, it is possible to achieve the lubricating and cooling effects of the fluid, to prevent seizing and wear, and to thereby stabilize the slipping state.
It is preferable to place a rotation intermitting device capable of intermitting the transmission of rotation in the course of the rotation transmitting path from the rotating member to the braking member. Since the rotation intermitting device makes it possible to apply an appropriate braking force and to remove the braking force, the braking force application property can be appropriately determined according to the usage of the mainspring mechanism. In this case, it is preferable that the rotation intermitting device cut off the transmission of rotation when the driving-force storing section stores the driving force, and transmit the rotation when the driving-force storing section emits the driving force. In this case, since the transmission of rotation is cut off by the rotation intermitting device when the driving force is stored in the driving-force storing section, the driving-force storing section and the braking section can be prevented from being damaged and broken in a case in which an excessive force is applied from the outside, or in a case in which the braking force excessively increases due to a decrease in temperature of a fluid resulting from a decrease in environmental temperature when the braking section produces a braking force by using the viscosity resistance of the fluid.
Another mainspring mechanism of the present invention includes a driving-force storing section having a mainspring to be wound up by a winding force so as to store a resilient force, and a mainspring holding portion connected to an outer end of the mainspring so as to hold the mainspring therein; a center member connected to an inner end of the mainspring; and a braking section for applying a braking force to the relative movement between the mainspring holding portion and the center member, wherein the driving-force storing section and the braking section are placed so that they do not substantially overlap in two dimensions, as viewed from the axial direction of the mainspring. According to this invention, since the driving-force storing section and the braking section are placed so that they do not overlap in two dimensions as viewed from the axial direction of the mainspring, they can be arranged so as not to overlap in the thickness direction, and this can reduce the thickness of the mainspring mechanism. When one of the driving-force storing section and the braking section becomes defective, it can be repaired without separating the sections, or without disassembling the other. Moreover, the driving-force storing section and the braking section can be independently and finely adjusted without being separated from each other or without disassembling one of them.
Herein, xe2x80x9cthe driving-force storing section and the braking section substantially do not overlap in two dimensionsxe2x80x9d device that an essential region of the driving-force storing section (that is, a region where the driving force is substantially stored) and an essential region of the braking section (that is, a region where the braking force is substantially produced) are arranged so as not to overlap each other. It is, of course, more preferable that the driving-force storing section and the braking section do not physically overlap at all in two dimensions.
The braking section may obtain a braking force from the flow resistance of a fluid such as gas or liquid. In this case, for example, the braking section may be composed of a rotatable braking member, and a fluid in contact with the braking member. Since a rotational resistance of gas is produced by providing the braking member with a wing, it can be used as a braking force. The flow resistance of a fluid other than gas in contact with the braking member may be used as a part of the braking force. This makes it possible to combine the braking using the gaseous resistance and the braking by the fluid other than gas. In this case, by placing the fluid other than gas only in a part of the space around the braking member, and increasing and decreasing the amount of the fluid, the braking force can be easily adjusted. Furthermore, the braking section may obtain a braking force by electromagnetic induction. In this case, for example, the braking section may be composed of a rotatable braking member, and a counter member opposing the braking member, wherein electromagnetic induction is produced between the braking member and the counter member (for example, a permanent magnet is placed in one of the braking member and the counter member, and a coil is placed in the other), and an electrical load against an induced electromotive force is connected thereto.
The mainspring includes a constant-torque spring and a coil spring used in such a manner as to receive and emit energy in response to changes in the winding state. The mainspring, the mainspring holding portion, and the center member may be connected by arbitrary device, such as press welding, hooking, or welding.
In the present invention, it is preferable that the braking section be placed on the outer periphery of the driving-force storing section. According to this invention, since the braking section is placed on the outer periphery of the driving-force storing section, it is possible to easily increase the operating distance and the braking area of the braking section. This can enhance the braking effect without increasing the size of the mechanism. For example, in a case in which the braking section includes a rotatable braking member, and a stationary counter member (for example, a braking case) disposed opposed thereto, when the braking member is connected to the driving-force storing section in the rotating direction and the counter member is placed outside the braking member, the operation of fixing the counter member by mounting onto another member is easily performed because the counter member is placed on the outermost side.
In the present invention, it is preferable that the braking section be placed inside the driving-force storing section. According to this invention, since the braking section is placed inside the driving-force storing section, after the braking section is completely assembled, the driving-force storing section can be connected thereto or can be assembled. This facilitates the assembly operation. Moreover, since the driving-force storing section can be easily disassembled, it can be subjected to maintenance and parts replacement, independently of the braking section. In a case in which the center member is fixed by being mounted to another member and the mainspring holding portion of the driving-force storing section is rotated so as to output a driving force, since the braking section is placed inside the driving-force storing section, the structure and position for extracting the driving force are not limited by the braking section. Of course, the driving force may be output from the center member.
In the present invention, it is preferable that an output device for outputting a driving force of the mainspring be connected to the driving-force storing section or the center member. According to this invention, an opening and closing structure and a moving portion can be directly or indirectly driven via the output device. Herein, xe2x80x9cthe output device is connected to the driving-force storing section or the center memberxe2x80x9d includes a case in which the output device is mechanically attached to the driving-force storing section or the center member, and a case in which the output device is formed integrally with a component of the driving-force storing section, or with the center member.
In the present invention, it is preferable that the driving-force storing section be hermetically sealed. According to this invention, since the driving-force storing section is hermetically sealed, it is possible to prevent dust from entering the driving-force storing section. Moreover, even when a high-viscosity grease is applied around the mainspring, it can be prevented from leaking out of the driving-force storing section. More specifically, it is preferable that the mainspring be enclosed by putting a lid on the aperture of the mainspring holding portion in the driving-force storing section.
In the present invention, it is preferable that a fluid in contact with the braking member be stored in the braking section and that the braking force be produced by the rotational resistance of the braking member with respect to the fluid. According to this invention, since the fluid is stored in the braking section, and the braking member and the fluid are in contact with each other, a high braking force can be ensured, and a stable braking force can be ensured. It is also possible to adjust the braking load in accordance with the viscosity of the fluid or the like, and to achieve various braking properties. Furthermore, since a sufficient braking force can be obtained with a small amount of fluid by adjusting properties, such as viscosity, the size of the braking section can be reduced.
In this case, it is preferable to provide an adjustment device for adjusting the contact area between the braking member and the fluid. By thus changing the contact area between the braking member and the fluid by the adjustment device, the braking load can be changed. More specifically, in a case in which the braking section includes a braking-member holding portion, and a braking member rotating therein, the fluid is in contact with both the inner surface of the braking-member holding portion and the surface of the braking member, and the resistance due to the flow of the fluid serves as the braking force. Therefore, the braking force varies depending on the contact area between the fluid and the braking member. In particular, it is preferable to increase and decrease the contact area of the fluid with the braking-member holding portion together with the contact area of the fluid with the braking member. As the adjustment device, any device may be used as long as it is capable of changing the contact area between the braking member and the fluid. For example, a device for moving the fluid and a device for changing the amount of the fluid may be used.
It is preferable that the space for storing the fluid in the braking section be extended toward the connecting portion between the braking member and the rotating member. Since the storage space in the braking section is extended toward the connecting portion between the braking member and the rotating member, the fluid is held in the storage space by its surface tension, and is prevented from flowing toward the connecting portion. Therefore, the fluid can be prevented from flowing outside through the connecting portion without adding a sealing member, such as a gasket, and a sealing structure. Since the rotational resistance resulting from the sealing member and the sealing structure is removed, energy loss can be reduced.
A further mainspring mechanism of the present invention includes a driving-force storing section having a mainspring to be wound up by a winding force so as to store a resilient force, and a mainspring holding portion for holding the mainspring therein; a rotating member to be rotated by the driving force of the mainspring; and a braking section for producing a braking force for the relative movement of the mainspring holding portion and the rotating member, wherein a power transmitting device for transmitting the rotation while increasing or decreasing the speed of the rotation is disposed between the driving-force storing section and the braking section. According to this invention, since the power transmitting device for transmitting the rotation while increasing or decreasing the speed of the rotation is disposed between the driving-force storing section and the braking section, the braking force can be increased or decreased by changing the speed-increasing ratio or the speed-reduction ratio of the power transmitting device. Since the braking force can be adjusted by the composition of the power transmitting device, it is possible to extend the range of choices of structures and materials of the braking section, and the like. Moreover, the degree of flexibility in the shape and size of the braking section is increased for a similar reason, and the relative positional relationship between the driving-force storing section and the braking section can be more freely determined because of the power transmitting device disposed therebetween. For example, the thickness of the mainspring mechanism can be reduced by placing the driving-force storing section and the braking section such that they do not overlap. In addition, it is possible to perform the assembly operation while adjusting the braking force of the braking section.
While the power transmitting device is, for example, a gear, a gear train having a plurality of gears, or a pulley and a transmission belt, any structure may be used as long as it transmits the rotation while increasing or decreasing the speed of the rotation.
The mainspring includes a constant-torque spring and a coil spring used in such a manner as to receive and emit energy in response to changes in the winding state. The mainspring, the mainspring holding portion, and the center member may be connected by arbitrary device, such as press welding, hooking, or welding.
In the present invention, it is preferable that the power transmitting device transmits the rotation of the driving-force storing section to the braking section while increasing the speed of the rotation. According to this invention, since the braking force can be increased in accordance with the speed-increasing ratio of the power transmitting device, the braking effect of the braking section can be enhanced, limitations on the structure of the braking section are reduced, and a wider range of structures and materials can be used. Furthermore, since the rotational driving speed of the driving-force storing section is made lower than the rotating speed of the braking section, the output rotation of the driving-force storing section can be easily controlled. This allows the driving speed to be controlled with high precision.
In the present invention, it is preferable that the braking section include a fluid, and a braking member in contact with the fluid, and that the braking force be produced by the rotational resistance of the braking member with respect to the fluid. According to this invention, since the fluid is stored in the braking section, and is in contact with the braking member, a large braking force can be ensured, and a stable braking force can be ensured. Moreover, the braking load can be adjusted in accordance with the viscosity of the fluid, and various braking properties can be achieved. Furthermore, since a sufficient braking force can be obtained with a small amount of fluid by adjusting properties, such as viscosity, the size of the braking section can be reduced.
In the present invention, it is preferable that the braking section has a braking member for producing the braking force by a rotational resistance thereof and that the braking member have a wing for receiving a gaseous resistance. According to this invention, since the wing receives a gaseous resistance when the braking member rotates, a rotational resistance is produced in the braking member by the gaseous resistance, and this resistance serves as a braking force. In particular, in a case in which the power transmitting device transmits the rotation of the driving-force storing section to the braking section while increasing the speed of the rotation, even when the gaseous resistance is low, a sufficient braking force can be ensured. Since the braking force is produced by the gaseous resistance, it is possible to adopt a simple structure, and to thereby reduce the size. The braking force may be obtained by also using the rotational resistance of a fluid other than gas together with the gaseous resistance. In this case, by placing the fluid other than gas only in a part of the space around the braking member, and increasing or decreasing the amount of the fluid, the braking force can be easily adjusted.
In this case, it is preferable that the braking section has an air-current suppressing face for covering at least a part of the outer peripheral portion of the braking member. According to this, since the air-current suppressing face is formed so as to cover at least a part of the outer peripheral portion of the braking member, an air current produced by the wing of the braking member can be prevented from separating from the braking member. This can further increase the rotational resistance by the gas. The air-current suppressing face may be formed of the inner surface of the braking-member holding portion which surrounds the braking member. It is preferable that the air-current suppressing face has an opening. Since this makes it possible to change the gaseous resistance in accordance with the number, position, and area of the opening formed in the air-suppressing face, the braking force can be adjusted.
In the present invention, it is preferable that the braking force be based on electromagnetic induction produced by the rotation of the braking member. More specifically, a braking member and a counter member disposed opposed thereto are provided, a permanent magnet is placed in one of the braking member and the counter member, an electromagnetic transducing device, such as a coil, is placed in the other. By connecting an electrical load to the electromagnetic transducing device, an induced electromotive force is generated in the electromagnetic transducing device by the rotation of the braking member, a current flows therethrough, and a braking force is produced in the braking member. While the braking force can be obtained according to an electrical load on the current (coil current) generated in the electromagnetic transducing device, at least a part of the electrical load can be utilized. For example, it is possible to cause a light-emitting element to emit light, and to cause a speaker to emit sound. Such light emission and sound emission can notify, for example, that braking is being done, or that the device is operating. Since the fluid is unnecessary, adjustment and maintenance can be easily performed.
In this case, it is preferable to provide an electrical-load changing device capable of changing the electrical load against the induced electromotive force produced by the electromagnetic induction. This allows the braking force to be changed by the electrical-load changing device. For example, the electromagnetic force can be increased or decreased, and the braking force can be adjusted by changing the (load) impedance connected to a coil. A variable resistor may be used as the electrical-load changing device.
In the present invention, it is preferable that the braking section has a slip portion where objects make contact with each other, and that the braking force be produced by a frictional resistance at the slip portion. According to this invention, since the braking force can be obtained by the frictional resistance at the slip portion, a simpler and more inexpensive structure is possible. In particular, in a case in which the power transmitting device transmits the rotation of the driving-force storing section to the braking section while increasing the speed of the rotation, a sufficient braking force can be obtained even when the frictional resistance is low, the wear of the slip portion can be reduced, and the lifetime of the slip portion can be prolonged. In this case, it is preferable that at least one of the objects forming the slip portion be made of an elastic material which exerts an elastic force on the other object in such a direction so as to press the other object. Since the frictional resistance can be stabilized by the elasticity of the elastic material and the elastic force to be applied to the sliding surface can be changed by changing the material and compressed state of the elastic material, the frictional resistance can be controlled by the elastic force, and the braking force can be adjusted.
In the present invention, it is preferable that the braking section has a speed control device. For example, in a case in which the flow resistance of the fluid is used as the braking force, such a speed control device is a device which adjusts the contact area between the fluid and the braking member and the amount of the fluid. In a case in which the gaseous resistance is used as the braking force, the speed control device is, for example, a device for adjusting the distance between the wing and the air-flow suppressing face, or a device for adjusting the aperture area of the air-flow suppressing face. In a case in which a braking force produced by electromagnetic induction is used, the speed control device is, for example, an electrical-load changing device (such as a variable resistor). In a case in which the frictional resistance at the slip portion is used as the braking force, the speed control device is, for example, a device for adjusting the pressure to be applied to the slip portion, such as the spring force of a coil spring.
In the present invention, it is preferable to provide a regulating device which can be engaged with and disengaged from the rotating member or the output device so as to regulate the output of the driving force from the mainspring. According to this invention, since the winding state of the mainspring can be maintained by the regulating device, operations of mounting into the device body and connection to another member are facilitated. Moreover, since the winding state of the mainspring can be set at a predetermined value beforehand by the regulating device, it can be prevented from varying. It is also possible to eliminate the necessity of adjusting and checking the winding state. It is preferable that the position of the regulating device be fixed (for example, engaged) by an immobile portion of the driving-force storing section or the braking section (a portion which does not respond to the rotation of the rotating member and the output operation of the output device, such as the mainspring holding portion or the braking-member holding portion of the braking section).
In this case, it is preferable that the regulating device has a plurality of engaging positions at which it engages with the rotating member or the output device. According to this, the winding state of the mainspring can be adjusted by appropriately selecting one of a plurality of engaging positions of the regulating device with respect to the rotating member or the output device. By forming a plurality of portions, where the position of the regulating device is fixed (for example, engaged) in an immobile portion of the driving-force storing section or the braking section (a portion which does not respond to the rotation of the rotating member and the output operation of the output device, such as the mainspring holding portion and the braking-member holding portion of the braking section), the regulating device can be engaged at a plurality of positions.
In the present invention, it is preferable to place a one-way clutch mechanism between the mainspring and the output device for outputting the driving force of the mainspring so as not to transmit the force from the output device in a rotating direction in which the mainspring is wound up and so as to transmit the force to the output device in a rotating direction in which the mainspring outputs the driving force. According to this invention, the mainspring can be wound up in a state in which the output section of the mainspring mechanism is connected to another member, for example, in a state in which the mainspring mechanism is mounted in a device such as an opening and closing mechanism. Therefore, it is unnecessary to wind up the mainspring into a predetermined state before the mainspring mechanism is mounted into the device, and to mount the mainspring mechanism into the device while maintaining the winding state. This can reduce the assembly time, the cost, and the like.
It is preferable that the present invention further includes an output gear for outputting the driving force of the mainspring, and a rack to be meshed with the output gear. According to this invention, since the mainspring mechanism can cause the rack to drive via the output gear, various devices can be slid.
It is preferable that the present invention further includes a fixing member for preventing the movement between the output gear and the rack. According to this invention, since the movement between the output gear and the rack meshed with each other in the output section (that is, a relative movement produced between the output gear and the rack by the rotation of the output gear) can be prevented by the fixing member, the mainspring mechanism can be mounted into a device or the like while keeping the mainspring in a predetermined winding state.
It is preferable that the present invention further includes a winding-number regulating device which disables the mainspring from being further wound after the mainspring is brought in a predetermined winding state. According to this invention, since the mainspring is disabled by the winding-number regulating device from being further wound up after it is brought into a predetermined winding state, it can be easily placed in the predetermined state without adjusting the degree of winding. Since an excessive and unnecessary force will not be applied to the mainspring, the durability of the mainspring can be increased.
In the present invention, it is preferable that the winding-number regulating device has a rotation connecting structure using the frictional force between the outer end of the mainspring and the mainspring holding portion. According to this, when the force to be applied between the mainspring and the mainspring holding portion is small, since a connection in the rotating direction is established by the rotation connecting structure because of the frictional force between the outer end of the mainspring and the mainspring holding portion, the mainspring can be wound up. When a force greater than a predetermined force is applied between the mainspring and the mainspring holding portion, the outer end of the mainspring and the mainspring holding portion slip each other, and the mainspring cannot be wound up further. This can simplify the rotation connecting structure, and therefore, the cost and size can be reduced.
A device of the present invention includes any of the above-described mainspring mechanisms, and a moving section to be driven by the mainspring mechanism. Such a device is not limited to a device having an opening and closing structure which will be described later, and any device may be adopted as long as it has a moving section, as in a moving toy.
In the present invention, it is preferable that the moving section be formed of an opening and closing mechanism to be opened and closed by the mainspring mechanism. Such a device having the opening and closing mechanism to be opened and closed by the mainspring mechanism is, for example, a device having a lid which pivots on a hinge shaft (a device having a pivotal opening and closing structure, such as a rise cooker or a folding electronic device) or a device having a portion which slides to be opened and closed (a device having a slidable opening and closing structure, such as a car-mounted drawer opening and closing mechanism, or a direct-acting retractable monitor). In these devices, the opening and closing operation can be performed at a controlled speed, and can be made more refined and more silent.
In the present invention, it is preferable that the opening and closing mechanism have a first member and a second member to be opened and closed relative to each other, and that the mainspring be wound up when the first member and the second member are assembled together. According to this invention, since the mainspring is wound up only by assembling the first member and the second member, which constitute the opening and closing mechanism, together, it is unnecessary to wind up the mainspring before the mainspring mechanism is mounted into the device. Since it is also unnecessary to set the degree of winding of the mainspring to a specified value, and to perform the mounting operation while maintaining the winding state, the operation can be easily performed, and the mounting time and cost can be reduced.
It is preferable to provide a range limiting device which limits the range of opening and closing of the first member and the second member to a range where the driving force of the mainspring is not completely released. The range limiting device also functions as a maintaining device for maintaining the assembly state of the first member and the second member in a state in which the first member and the second member are assembled together. When the first member and the second member are assembled together, the range of the opening and closing operation thereof is limited by the range limiting device, and the driving force of the mainspring is not completely released. Since this can stabilize the driving force of the mainspring over the full opening and closing range, the opening and closing operation can be performed reliably.
In the present invention, the moving section includes a moving portion of a toy.